1. Field of the Invention
The invention refers to a drift advancing or mining machine, in particular equipped with a caterpillar chassis, comprising a cutting arm on which are arranged cutting heads and/or cutting rolls being rotatably supported for rotation around an axis transversely extending to the drift advancing direction.
2. Description of the Related Art
In usual cutting machines of the initially mentioned type, there is supported on a caterpillar chassis a cantilever arm or cutting arm, respectively, for being swivellable around an essentially vertical axis and around a substantially horizontal axis. For effecting excavations of greater cross-sectional area, the cantilever arm must be given a corresponding length, noting that when swivelling the cantilever arm in a lateral direction or in a height direction there results an essentially curved mining face. In the case of fragile drift roofs, it is necessary to effect the provisional consolidation of the drift near the mine face for preventing a collapse of the drift roof. Such a provisional consolidation is relatively expensive and time-consuming and can--in consideration of the also laterally swivellable cutting arm or, respectively, cantilever arm--not be moved arbitrarily close to the drift face. Furthermore, such a provisional consolidation requires correspondingly more expensive appliances for transporting the consolidating frames and auxiliary means for effecting the consolidation above the cutting machine located in front of the drift face, but the space at disposal near the drift face is correspondingly restricted. Additionally, with known devices it is only possible to erect the consolidation in proximity of the drift when stopping the cutting work, because a reliable protecting means can not be arranged between the cutting tools and locations located in proximity of the drift face, because such protecting means would collide with the cutting arm.
From DE-PS No. 29 30 136 there has become known a drift advancing machine for underground mining in which a track for a shiftably arranged support carrying cutting tools is provided on a stationary equipment being stabilized against the drift roof and the drift floor. Such a construction is relatively difficult to manuever and requires a relatively great space in the direction of the longitudinal drift axis. The cutting means are designed as augers and rotatable around axes substantially extending in the longitudinal direction of the drift. Together with the swivellable cantilever arms provided in this construction there results a relatively great total axial length.